


Fire and Water

by AvocadoLove



Category: Avatar: The Last Airbender, Naruto
Genre: Crossover, Crossovers & Fandom Fusions, Episode: s01e19-20 The Siege of the North, Firebender Kakashi, M/M, Waterbender Iruka
Language: English
Status: In-Progress
Published: 2017-05-08
Updated: 2017-05-08
Packaged: 2018-10-29 14:28:50
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 3
Words: 3,192
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/10855908
Author URL: https://archiveofourown.org/users/AvocadoLove/pseuds/AvocadoLove
Summary: Naruto/Avatar: The Last Airbender FusionWaterbender Sifu Iruka meets firebending Commander Kakashi during the Siege of The North.(Originally posted on my LJ in 2010)





	1. Chapter 1

**Author's Note:**

> Note: This fic ends on a cliff-hanger note. I do plan to add more in the future, but not before I finish some of my other ongoing fic projects.

_Note: Original prompt based on this pic found in the old KakaIru kink meme_

 

 

 

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* * *

 

“…Which is why you should always be aware of the phase of the moon and adjust for it,” Iruka concluded. He paused for a moment to let that point sink in, looking over his group of students sitting cross-legged in the snow. “Now, which phase of the – Konohamaru, finish that and you’ll be gutting fish after class all next week!”

The guilty boy froze, a mitten-full of icy slush hovering inches over the back of Nilak’s parka. At Iruka’s stern glare, the slush dropped and refroze harmlessly on the ground.

“Since you know so much about waterbending, you feel you don't need to pay attention,” Iruka said in a deceptively controlled voice which made all of his student's spine's straighten in fear, “Please tell the class which phase the moon is in right now.”

Konohamaru screwed up his face in thought. “… Uh, waxing gibbous?”

“Correct. Which means…?”

The boy brightened. “Tomorrow it’ll be full and us waterbenders will be at our full power! We’ll be unstoppable!” He went on before Iruka could stop him or correct his atrocious grammar. “Sifu Iruka, does that mean it’s like the moon is always full for the Avatar? Because he’s so powerful?”

Iruka resisted the very strong urge to pinch the bridge of his nose in frustration. The class – normally fidgety and hyperactive on the best of days – had been nearly out of their minds with excitement ever since the Avatar and his companions from the Southern Tribe had arrived.

“I assure you, I don’t know,” Iruka answered. “Now, while the moon is full—“

Udon raised his hand, but did not wait to be called on before he spoke. “But if the Avatar is just starting to learn waterbending, shouldn’t he be in the beginner class with us?” he asked and all of the boys nodded seriously around him.

“Sifu Pakku is in charge of instructing the Avatar with his advanced class. If you want to be trained with him then you must work hard and hope Pakku takes you as his student.” Udon opened his mouth again, but Iruka cut him off sharply. “That is enough about the Avatar. Today’s lesson is about the moon— _What_ Konohamaru?!”

“Sifu, why is it snowing black?”

“W-what?”

Iruka looked up. The sky was a clear, frozen blue. And floating down, like bits of visible death, were blackened snowflakes. One landed on the sleeve of his parka and Iruka brought it to his eyes for a closer look. Sure enough, the snow had been stained with soot.

Iruka knew what it meant, even if the boys didn’t. They were getting loud again; exclaiming in amazement or disgust as the nearby fountain turned black with falling grit.

“Quiet down, all of you!” Iruka was pleased, despite himself, how he managed a calm authoritative voice. “Class is dismissed for today, but you are all to head straight to your homes. No exceptions.”

Konohamaru looked at him with wide eyes. “You never let us out early. What’s going on?”

Somehow, Iruka managed a reassuring smile. “I don’t know yet, but we will find out soon. Do what you’re told.”

The boys left and scarcely a minute later the bells over the ice palace began to toll.

Iruka felt his heart drop to his stomach. It meant only one thing: The Fire Nation was invading.

 

* * *

 

****

* * *

 

 

  
Miles out to sea, an armada of steel-plated warships tugged steadily northwards – billows of coal-choked air rising from each one.

And deep within the bowels of one random ship stood a man, leaning idly against on of the warm boiler room walls, his nose stuck in a little orange book. Or at least, what could be seen of his nose. The lower half of his face was covered by a thin, dark mask, and his right eye hidden by a jauntily angled bandanna emblazed with the Fire Nation insignia. He stood quiet and undisturbed… but waiting. Clearly waiting.

Suddenly the torches along the walls and the kerosene lamp at his side flared Dramatically. Another figure leaped into view – the flickering light seemed to turn the new-comer’s red and gold uniform a garish green for the briefest of moments.

“Ah! I have found you at last, my most esteemed rival!”

The first man made no reaction at all, his half lidded eye trailing slowly over the page in front of him. “Yo.”

"You are just too youthful and hip for me, Kakashi!" Commander Gai said, striking a pose with his thumbs up. His bright teeth glinted in the firelight. "I swear to defeat more waterbenders than you or I will run the length of this ship twenty times on my hands! I have come to offer you a challenge!"

When Kakashi made no move, the smile slipped slightly from Gai’s face. He cast a glance around and spoke quietly (for him). “Don’t tell me you are concerned about our upcoming glorious campaign? We are led by the brave Admiral Zhao, who has advanced in rank faster than no other! Not to mention the esteemed Dragon of The West, who, even in his time of grief for his precious nephew—”

“I served under Iroh at Ba Sing Se,” Kakashi interrupted, casually flipping another page. “I have seen him grieve before.” And all the earthbenders who fell as a result. That whole platoon…

“While it's true General Iroh is not in the springtime of his youth, I’m sure his Flame of Honor burns—” Gai stumbled to a halt as his brain caught up with his mouth. Despite what some may say about him, Kakashi knew the other commander to be surprisingly perceptive. “Ah,” Gai said, with a knowing nod. “You believe The Dragon of The West has his own plans.”

Kakashi rolled a shoulder in a lazy shrug. “I think something interesting may happen.” A pause. “Have you happened to notice the moon, recently?”

“Yes! I find it most invigorating to train by the light of the moon. It strengths my eyesight and fans my inner fire ever hotter—”

“It is nearly full.”

“Yosh!” Gai exclaimed again, punching his fist into the air. “As we draw our power from the brightly burning sun, so do the dishonorable barbarians seek theirs from the moon. Very clever, my eternal rival!”

“Well, that is why I am a genius.”

Then Gai fell silent for a moment, thinking. When he spoke, his voice was as solemn as Kakashi had ever heard it. “We have better ships, more youthful and vigorous crew. Yet the sun does not shine so brightly in the poles, while the moon will be full. We are being sent into a disadvantage. Why?”

Kakashi glanced up. His visible eye was hard and flinty. “Why, indeed?”

“Hmm. Then I vow to train even harder than before!” Gai beamed. “I will run fifty times around the ship and perform no less than five-hundred hot-squats! You must spare with me, my eternal rival, so that we will be at the very peak of our strength against our foe!”

Kakashi hesitated, and then shut his book with a snap. “I think I will.”


	2. Chapter 2

Only the heads of the houses were to attend Chief Arnook’s war council. Iruka stood in the courtyard outside the palace doors, waiting among the lower ranked men and the women for news.

Finally, the tall iced doors opened and the crowd as a whole pressed forward to hear the news. Iruka kept himself back, standing on tip-toes to see if he could spot his friend, Mizuki, in the crush. He would tell him what was going on.

“Sifu Iruka?”

He turned. A girl stood behind him, dressed in odd light blue clothing. Iruka recognized her at once from the village gossip: she was the Southern Water Tribe girl, the companion of the Avatar and the one who had challenged Master Pakku for her right to be taught waterbending like a man.

She bowed politely, one hand enclosed in a fist, and he returned the favor – one waterbender to another. It felt odd, making the gesture to a female. Strange, but not offensive.

“Master Pakku sent me to tell you that he wishes to speak to you,” the girl – what had her name been? Kanara? Katana? _Katara_. – said, “He wants to know which of your students will be ready to help on the wall.”

Iruka’s mind stuttered briefly to a halt. _None_ , he wanted to snap. _They’re still children! They don’t belong in war._

But he knew that wasn’t fair. The Fire Nation wouldn’t care if some of the boys weren’t old enough to lose their milk-teeth yet. Just as long as they burned. “Is it that bad, then?” he asked, after a shocked moment.

Katara bit her lower lip and nodded. “It looks like the Fire Nation has sent their full armada.” Then she brightened. “But Aang is going to fly out and do what he can. If anyone can stop the Fire Nation, it’s him.”

“Yes,” Iruka replied, feeling oddly hollow inside. He had seen the Avatar and had heard Pakku’s grumbling about the boy. He, too, was only slightly older than some of Iruka’s students.

Someone called Katara’s name. She turned and waved back before politely excusing herself.

With a growing sense of foreboding, Iruka turned and went out in search of Pakku. The list of ready students taking shape in his mind.

Yes, he understood the necessity of it, but Pakku must be a water-logged idiot if he thought Iruka was going to send his boys into war without a fight. 

 

* * *

 

  
****

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The hardest part about any battle was the wait.

Admiral Zhao chose the positions of the ships well, opening up the engagement with ship-board catapults hurling flaming boulders at the huge wall of ice that shielded the Northern Water Tribe village from the ocean. This wall acted as a shield and would have to be breeched before the ground-level firebenders could be sent in.

Kakashi watched from the deck as boulder after boulder smashed against the wall. He stood silent, observing with calm indifference as, after a hit was made from the ice, there would be a flurry of activity from tiny figures on the wall clothed in deep blue – waterbenders, most likely – and any cracks in the ice would reform itself.

They were like ants scurrying back and forth in face of a forest fire.

He watched, too, as a large sky bison swooped down from above, its rider landing on the deck and disabling ship after ship. This had to be the mysterious Avatar he’d heard so much about. Kakashi was interested enough to raise his headband and get a look with both eyes. But there were far more ships than one lone airbender could handle.

The Avatar never even came within firing distance of Kakashi’s ship. All the crew could do was watch. Eventually, even Kakashi tugged the strip of cloth back down over his eye.

“So troublesome,” a voice said beside him, a young ensign named Shikamaru.

Kakashi glanced over, but the ensign was not watching the Avatar or the assault on the ice wall. He had his head tipped up and was looking at the movement of the wispy polar clouds overhead. "You have thoughts to share, Ensign?"

“The Water Tribe hasn’t launched any other counter-attack yet, other than him,” Shikamaru continued, waving a lazy hand at the direction of the swooping sky bison. “Are they going to allow Zhao to beat down their wall until we come in?”

Kakashi shrugged. “It is the nature of waterbenders to redirect attacks. They may have something planned once the Admiral punches through.”

“ _If_ we get through.” The ensign sighed. “It would be so much less effort to just sit here and starve them out.”

“Maa, then Admiral Zhao wouldn’t have his great victory, and then where would we be?” Kakashi was silent for a moment, turning back to the shield wall. The feeling of unease – instinct honed by years on the front lines in the Earth Kingdom – was nearly shrieking at him now. Something was wrong with this battle. Something lurking so far underneath the underneath that Kakashi wasn’t able to see it clearly. But he could smell it. It smelled like rot.

“I am making a change in the roster,” Kakashi said, at last. “You will accompany me during the ground assault.” His original plan was to keep Shikamaru as part of the skeleton crew on the ship. The boy was no powerhouse at firebending, being more of a natural tactician. But Kakashi had promised Asuma that he was going to keep his apprentice safe, and closer to battle it became, the more he was convinced that the best way to do that was to keep the kid right by his side.

Shikamaru studied his commander for a long, quiet minute. Most teens his age were hot-blooded for battle. Shikamaru was about as cool and unambitious as Kakashi had ever seen in a firebender, yet he didn’t miss the connections being made behind the boy’s eyes. Perhaps he too, sensed something strangely off.

The ensign gave a sigh and nodded in acceptance, another muttered, “Troublesome,” before he turned to watch the clouds once more.

 

 


	3. Chapter 3

Despite Shikamaru’s pessimism, the Fire Nation catapults managed to punch several holes in the walls late into the afternoon. These were sealed within minutes by waterbenders, but to Kakashi’s eye, the ice which was refrozen over the gaps seemed thinner, more translucent than before.

A sign their enemy was tiring.

Admiral Zhao called for a halt just after dusk, allowing the catapult crews to rest; there would be no fighting the Water Tribe during the night when their strength was at their peak.

As the weak polar sun broke on the second day of the siege, the catapults began again. Soon, the overwhelmed wall cracked and fell into the sea, allowing the warships to move forward. It was almost noon by the time the bow-spirits crashed down and Kakashi and the rest of this command stepped into the village of ice and snow.

He had no time to admire the view – the streets filled with water, archways and sidewalks and houses all carved from the same hard-packed ice. Everything was crisp and clean here. The air was so cold it twinged inside his chest to inhale too deeply.

He couldn’t help but notice how the ice soon became tinged with soot, warped by heat at their passing.

It was the type of fighting that Kakashi disliked the most: Stepping forward, locked shoulder to shoulder with the rest of the firebenders. They moved forward steadily rank by rank, wearing down the enemy with timed fireblasts and discipline.

Kakashi was an independent fighter by specialty, and by the time evening fell the orders came down from the top for his platoon to break off into pairs and engage the Water Tribe separately. Waterbenders were to be rounded up and contained while Zhao’s personal forces went forward to secure the capital.

“The Water Tribe warriors will cower in the face of my youthful vigor!” Gai declared, posing dramatically in front of the setting sun and the shattered remains of what might have once been a storefront. “Come, my adorable apprentice! Today, we test our skills against those who threaten our glorious Fire Lord!”

“Yosh!” Lee declared, a younger version of Gai himself. And together, they jogged down one of the many streets carved in ice.

Shikamaru and Kakashi watched them leave, expressions of boredom and apathy on their faces.

“Come on.” Kakashi jerked a thumb in the other direction.

Their pace was much slower through the streets, although no less dangerous. Women and children fled at their approach, screaming. And for the most part, the commander and ensign let them go, only sending fire out to speed them on or when they looked as if they were going to turn and attack.

Night fell quickly this north of the polar circle, and Kakashi kept an ear cocked for signal horn to fall back. Surely Zhao knew the full moon was due to rise soon…

A flicker of movement caught Kakashi’s eye just as they were ducking under a walking bridge. Kakashi yelled out a warning and lurched to the side, but it was too late. With a muffled thump, he suddenly found himself neck-deep in a powdery pile of snow.

A childish cheer broke out from above. He looked up to see three young Water Tribe boys grinning down at him from the top of the bridge.

“Take that, firebender!” one boy shouted, and threw a snowball down which missed Kakashi’s face by inches. “Get outta our village!”

 _I hate kids_ , Kakashi thought. It took only a moment’s concentration to melt the snow enough to crawl out. Beside him, the mound of snow covering Shikamaru caved in slightly, as the shorter ensign did the same. Another snowball flew just past his nose.

Kakashi had enough. Taking in a deep breath to call his fire, he leaned back and flicked his wrist in a snap – a whip of orange flame uncoiling and crackling out before him. It hit the base of the walkway just to the side of the three brats, exploding through ice and snow.

The kids shrieked and fell over each other trying to scoot out of the way. Kakashi aimed his fire-whip again, a little ahead of their path this time. The walkway was not so far from the ground that they would be killed if it collapsed, but the fall should stun them enough to make it easy for a capture-–

PLOOSH.

The stream of water under the walkway rose to a wave within a moment, drenching Kakashi from head to foot. His flame was extinguished.

The children cheered.

A shadow detached itself from under the walkway and moved forward into the light. It was man about Kakashi’s age, although a touch shorter and bulkier, dressed in dyed blue skins of the Water Tribe. And, judging by the nearly effortless way the water rose again to his command – circling into a globe between his tanned fingers – a waterbender of some skill.

The waterbender glared at him, then glanced up to the walkway. “Get your friends out of here, Kohonamaru. I’ve got these two.”

Kakashi looked over his shoulder to Shikamaru, who had just now crawled free of the snow. “Go after them,” he said, jerking his chin to the retreating children.

“No!” The waterbender shot a deadly tendril of water towards the ensign, but Kakashi’s quick burst of fire dispersed and broke it apart before it hit.

And as Shikamaru ran off in pursuit of the annoying kids, Kakashi stepped in front of the waterbender.

The other man’s eyes narrowed -- there was a scar across the bridge of his nose which extended to both cheeks – and he sunk down into a low stance; something strong and graceful.

Kakashi’s heart was pounding, although he wasn’t afraid. He nodded and stiffened his stance, extending an arm out and ready to call his fire.

The two men stood like that for the space of five heartbeats.

Then they struck.

 


End file.
